A mechanical timepiece movement generally includes a barrel system driving at least one wheel at the winding output and one wheel at the unwinding output respectively connected to a winding wheel and to an unwinding wheel of a differential gear. A set of wheels connected to an intermediate wheel of the differential gear controls a power reserve display, but no element of the movement is provided for an operation to stop the movement when the power reserve is at zero.
EP Patent 0 568 499 B1 describes a power reserve indicator device for a mechanical watch. The indicator device includes at least one star-wheel with an indicator member, which is driven in rotation during the winding or unwinding of the barrel. The indicator member makes it possible to display the power reserve of the watch. However, nothing is provided to ensure that the movement is stopped when the power reserve approaches zero.
CH Patent 698 752 B1 describes a timepiece which includes a power reserve indicator mechanism. It includes two barrels facing each other and connected by a common arbor, which controls the power reserve display mechanism. However, nothing is provided to ensure that the movement is stopped when the power reserve approaches zero.
EP Patent 1 970 778 B1 may also be cited, which describes a timepiece with a movement and a power reserve indicator device. This timepiece includes a barrel system mounted between a watch plate and a bar. The power reserve indicator device includes a differential gear connected by a first input to the barrel arbor and by a second input to the barrel. The differential gear is arranged coaxially to the barrel arbor. The barrel output is connected to a power reserve indicator member. Nothing is provided to ensure that the movement is stopped when the power reserve approaches zero.